1. Technical Field
The present invention relates to a driving method of an electrophoretic display device, an electrophoretic display device, and an electronic apparatus.
2. Related Art
In recent years, a display panel having a memory ability, which is capable of retaining an image even though power is cut off, has been developed and used for an electronic watch or the like. As the display panel having the memory ability, an EPD (electrophoretic display) device, a liquid crystal display device having a memory ability, or the like has been proposed.
In the electrophoretic display device, it is known that a display change occurs according to an environmental temperature. An electrophoretic display device disclosed in JP-A-2004-085606 changes the intensity of an electric field generated between a common electrode and a pixel electrode by controlling a driving voltage according to an environmental temperature. For example, in a case where the environmental temperature at which the electrophoretic display device is used is low (hereinafter, referred to as a low temperature), the driving voltage of a pulse signal applied to the electrodes is set to be high to strengthen the electric field, thereby preventing contrast from being lowered.
Here, the contrast has the same meaning as a contrast ratio. That is, in an electrophoretic display device which uses black and white as basic display colors, the contrast refers to the ratio of an arrival reflectance indicating white and an arrival reflectance indicating black. In the electrophoretic display device, even though the electric field is continuously applied between the common electrode and the pixel electrode, the reflectance is saturated. The arrival reflectance refers to the saturated reflectance. The arrival reflectance is changed according to an operation condition of the electrophoretic display device including the environmental temperature.
In this regard, it has been experimentally confirmed that even though electric power (driving voltage×driving time) of a pulse signal supplied to a common electrode and a pixel electrode is increased, in a case where partial driving is performed at a low temperature, contrast is lowered. That is, in a case where the partial driving for rewriting in only apart of a display section is performed at the low temperature, even though the driving voltage of the applied pulse signal becomes high or even though the driving time thereof becomes long, the contrast is lowered compared with the case of a temperature other than the low temperature. Thus, a display quality of the electrophoretic display device may deteriorate.